AirTran has offered $35 upgrades from full-fare coach to its slightly-better business class—a good deal, no doubt. However, AirTran is doing one better by offering these upgrades on ALL fares. In short: When checking in, if space is available in business class, you can upgrade for $35 ($50 from Denver, San Francisco, Vegas, and LA) or $70 for connecting flights ($85 from the above 4 cities). Great way to get a bit extra space for a reasonable upgrade fee. No, I don’t know why other airlines don’t do this.